Plant of the Month: December, 2000

by Russell Stevens

Tansy Mustard
Descurainia pinnata

Characteristics: Tansy mustard is an annual cool-season native forb found in disturbed areas, old fields, and waste places. It is most abundant on dry, sandy soils. It can reach 32 inches in height. Leaves are blue-green, alternate, and usually bipinnately compound (branched twice). Stems are erect and may be solitary or multiple and are sometimes branched. Flowers are numerous and have four petals, are bright yellow to white, and sit at the top of an elongated terminal spike. Fruits are club-shaped, shorter than their pedicels (stems), and located along the terminal spike below the flowers and above the leaves.

Area of Importance: Throughout Oklahoma and Texas.

Attributes: Current use is minimal. Historically, tansy mustard seeds were ground by Native Americans to make meal or flour or were roasted and added to foods. Tansy mustard reportedly has medicinal uses as well. Birds may eat seeds.

I.D. Tip: Look for bright yellow flowers in early spring, with club-shaped fruits below them. Look in poorly maintained wheat fields and along roadsides and other disturbed areas on sandy soil.

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Hundreds of plants are identified in the Noble Foundation Plant Image Gallery.